No. 2 post - Top and bottom locking end., No. 3 post - Bottom locking intermediate cylinder control., No. 4 post - Bottom locking intermediate spring lock., No. 5 post - Bi-part hook bolt into bottom locking striker., No. 6 post - Self locking with V plate on floor and top track which catches hook on end post., No. 7 post - Hook bolt and wall striker., No. 8 post - Fixed end.